Improving thermal plaster performance by means of recycled materials and Phase Change Materials

The new and tighter regulations concerning energy efficiency in buildings, set forth by the European EPBD directive, pose new challenge in the field of building envelope components. A research was started concerning the adoption of thermal insulating plasters as a mean to improve the energy saving for space heating and cooling. These materials, in fact, thanks to their relatively easy installation, represent a good solution both for new constructions and for the energy refurbishment of existing buildings (which constitute the large quota of the stock, being the new construction rate of about 1 % per year in Europe). As a first step, traditional materials and technologies for thermal plaster were tested in the laboratory, by means of an hot plate apparatus. Subsequently, new aggregated (thermally insulating) materials were analysed, with a particular focus to vegetal remainder of different kinds of processes and/or to waste materials. As a last phase, these plasters were coupled with Phase Change Materials (PCM) in order to improve both the thermal insulation and thermal inertia of the layer. Different configurations (layers distribution) and various quantity of PCM were studied. For this last activity, dynamic tests were performed by means of suitable sinusoidal excitation generated inside the hot plate apparatus. In the paper measurement methods and data analysis will be described. Results related to the expected improvements of the thermal plaster performances will be presented and critically analyzed.